We found a simply beautiful Raspberry Pi project over at Instructables: this illuminated lunar phase clock.

Using John Conway’s lunar phase algorithm (that’s the same John Conway who invented the cellular automaton Game of Life in the 1970s), some simple circuitry (some soldering required, but this is an easy enough job), and a bit of elbow-grease for that handsome case, Aleator777 has produced an excellent tutorial that gives you all the steps you need to create your own lunar clock.

We love artistic, decorative projects like this one – and it’s a good way to teach your kids a little astronomy. Suggestions for improvements? (We note, for example, that Conway’s lunar phase algorithm only works for this century and last century.) Leave them in the comments!

Well the moon’s rotation is tidally locked to the earth now, but I imagine at some point in the past, it wasn’t… anyway that is a very beautiful clock. Could add a PWM driver to fade in each segment gradually, for higher resolution.

The moon does rotate, it’s period of rotation is equal to its orbital period. When there is a new moon the far side is illuminated, as the moon waxes the illuminated hemisphere moves towards the side facing the Earth until at full moon the far side is in darkness. As the phase of the moon wanes the hemisphere that is illuminated moves towards the far side until it gets back to new moon.

Many people *do* have access to a hackspace or makespace in their local area, though; it’s worth looking around. (And the project author notes that the casing can be made by traditional methods if you have the time and skill.)